One vertex per element, one color per generator, with an edge from x to x·s.
(3,7)(6,8)(9,10,13,16)(11,17,19,14)(12,20,22,15)(18,23,21,24)(25,26,30,34)(27,33,29,31)(28,32,38,36)(35,40,37,39)(1,2)(3,6)(4,5)(7,8)(9,11,13,19)(10,14,16,17)(12,18,22,21)(15,23,20,24)(25,27,30,29)(26,31,34,33)(28,35,38,37)(32,39,36,40)(2,5)(6,8)(9,11,13,19)(10,14,16,17)(12,21,22,18)(15,24,20,23)(25,26,30,34)(27,31,29,33)(28,36,38,32)(35,40,37,39)(1,2)(3,6)(4,5)(7,8)(9,11)(10,14)(12,18)(13,19)(15,23)(16,17)(20,24)(21,22)(25,26)(27,31)(28,32)(29,33)(30,34)(35,39)(36,38)(37,40) involution — undirected(1,2)(3,6)(4,5)(7,8)(9,12,13,22)(10,15,16,20)(11,18,19,21)(14,23,17,24)(25,28)(26,32)(27,35)(29,37)(30,38)(31,39)(33,40)(34,36)(1,3,4,7)(2,6,5,8)(9,10)(11,14)(12,15)(13,16)(17,19)(18,23)(20,22)(21,24)(25,29,30,27)(26,33,34,31)(28,37,38,35)(32,40,36,39)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.